A broadband ion beam analyzer is a core component of an implanter and is used to isolate ions under the influence of a magnetic field or an electrical field according to the mass-to-charge ratio.
A broadband ion beam analyzer in the prior art comprises an upper magnetic pole and a lower magnetic pole, the upper magnetic pole and the lower magnetic pole are respectively connected to an upper excitation coil and a lower excitation coil, while both of the upper excitation coil and the lower excitation are connected to an electrical source. When being electrified, a magnetic field will be generated in the space between the two magnetic poles, and ions with different mass-to-charge ratio have different deflection radius in the magnetic field. Therefore, the analysis grating disposed in the space between the two magnetic poles enables the required ions to be isolated from other ions in the broadband ion beam. The required ions will pass through the analysis gap of the analysis grating, while other ions are shielded by the analysis grating. The upper magnetic pole and the lower magnetic pole are both provided with an incident-end boundary and an emergence-end boundary. The broadband ion beam is emitted into the magnetic field from the incident face of the magnetic field at the side of the incident-end boundary, and is emitted out of the magnetic field from the emergence face of the magnetic field at the side of the emergence-end boundary after being deflected for 180° in the magnetic field and focusing at the mid-section of the magnetic field to form a focal spot. As for the broadband ion beam analyzer in the prior art, since the incident-end boundary and the emergence-end boundary of the upper magnetic pole and the lower magnetic pole are planes or curved surfaces, after the broadband ion beam being emitted into the magnetic field from the incident face of the magnetic field, the required ions can not focus ideally, that is, focal spot's size does not equal to zero. Further, since the width of the analysis gap of the analysis grating must be at least larger than the size of the focal spot, a large analysis gap allows ions besides the required ions to pass therethrough, which makes it hard to completely isolate the required ions from other ions.